1. Field of the Invention
This invention relates to optical fiber tuning. More specifically, the invention is an optical assembly that can be used to tune an optical fiber while also providing vibration dampening therefor.
2. Description of the Related Art
Strain tuning of optical fibers is known in the art and is currently accomplished in a variety of ways to include the use of piezoelectric and magnetic actuating elements. In terms of piezoelectric actuating elements, a stack of piezoelectric elements is typically required in order to provide the needed amount of mechanical movement because, in general, piezoelectric materials are not capable of producing large amounts of mechanical displacement upon actuation. Thus, the requirement that a stack of piezoelectric elements be used adds to the weight of an optical fiber tuning system. See, for example, U.S. Pat. No. 6,240,220. In terms of magnetic actuating elements, a multiplicity of magnets are used to stretch tune an optical fiber. See, for example, U.S. Pat. No. 5,999,546. However, the magnets are relatively heavy and bulky, and can be adversely affected by environmentally-present magnetic fields.
The stretch or compression (i.e., strain) tuning of an optical fiber is critical for a tunable fiber laser. In these types of lasers, an optical fiber having one or more Bragg gratings is strain tuned to provide a desired lasing wavelength. However, the Bragg gratings are sensitive to vibrations so that a tuning mechanism should also ideally provide vibration dampening for an optical fiber's Bragg gratings.